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基于不同退耕模式的黄土丘陵区生态环境建设地域分异特征 总被引：2，自引：0，他引：2
退耕是目前国家关于黄土丘陵区生态环境建设的主体措施。在总结"赈济退耕25"、"赈济退耕15"和"梯田退耕"各模式基本特点的基础上,根据土地利用、耕地坡度分级数据、农业人口数据和不同模式生态环境建设标准,分别计算了黄土丘陵区各县(市、区)退耕25°和15°以上坡耕地、新建园地、新修梯田、林草植被恢复的面积以及相应的投资需求额度。在构建并采用生态环境建设指数、政策性补贴资金密度指数和投资需求密度指数等指标,对55个县(市、区)进行类型划分的基础上,分析了黄土丘陵区不同退耕模式下的生态环境建设规模及投资需求地域分异特征。 相似文献
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WANGLiming FENGRenguo YANGYanfeng GUANQingfeng 《山地科学学报》2004,1(1):89-95
As an important measure of ecoenvironmental construction, the process of de-farming in slope farmland is being undertaken gradually in the whole China. Meanwhile, the problem of reducing in food yield in de-farming areas can not be neglected any more. It is especially the case in areas with concentrated slope farmland and inconvenient transportation. In this paper, we analyze the causes of hidden troubles in food security, and the spatial relationship between farmland and slope farmland in the reservoir area of Three Gorges, and unveil the spatial disparity of contradictions between food supply and demand. Finally, combining the accessibility of areas, three different spatial types of food security, food security area, food alert area, and food crisis area, are divided. 相似文献
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黄土丘陵区不同生态重建模式评价方法 总被引：1，自引：0，他引：1
1IntroductionIn a long history of land use and exploitation, in order to meet the demand of quickly increasing population for food supplies, China has accumulated many successful and unsuccessful experiences in promoting economic development by using land… 相似文献
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The project of ‘grain for green’, to restore woodland and grass by retreating from slope farmland, as a fundamental measure
of eco-environmental rehabilitation, is being conducted in the reservoir area of the Three Gorges gradually. However, the
de-farming of slope farmland will reduce the amount of farmland in de-farmed areas, especially in the areas with concentrated
slope farmland, which would cause the problems of environmental emigration. The people who cannot regain enough farmland by
relocating farmlands within village after de-farming and have to emigrate to other places are called environmental emigrants
or ecological emigrants. In the research, a de-farming stress index model and an environmental emigration model are developed
based on GRID data, and the potential amount of environmental emigration caused by de-farming of slope farmland in the reservoir
area is simulated aided with GIS. The simulation indicates that the potential emigration amount caused by de-farming is quite
large. When the de-farming stress index reaches 40%, the amount is as large as 890,000 people, which is equivalent to the
emigrants caused by the submergence of the Three Gorges reservoir. So it should be considered as a big problem during the
eco-environmental rehabilitation in this area. Some suggestions are raised to tackle the problem. Firstly, the emigration
plan should be included in the de-farming plan. Secondly, some provinces, especially those located in the lower reaches of
the Yangtze River, should accommodate part of the environmental emigrants. 相似文献
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The project of 'grain for green', to restore woodland and grass by retreating from slope farmland, as a fundamental measure of eco-environmental rehabilitation, is being conducted in the reservoir area of the Three Gorges gradually. However, the de-farming of slope farmland will reduce the amount of farmland in de-farmed areas, especially in the areas with concentrated slope farmland, which would cause the problems of environmental emigration. The people who cannot regain enough farmland by relocating farmlands within village after de-farming and have to emigrate to other places are called environmental emigrants or ecological emigrants. In the research, a de-farming stress index model and an environmental emigration model are developed based on GRID data, and the potential amount of environmental emigration caused by de-farming of slope farmland in the reservoir area is simulated aided with GIS. The simulation indicates that the potential emigration amount caused by de-farming is quite large. When the de-farming stress index reaches 40%, the amount is as large as 890,000 people, which is equivalent to the emigrants caused by the submergence of the Three Gorges reservoir. So it should be considered as a big problem during the eco-environmental rehabilitation in this area. Some suggestions are raised to tackle the problem. Firstly, the emigration plan should be included in the de-farming plan. Secondly, some provinces, especially those located in the lower reaches of the Yangtze River, should accommodate part of the environmental emigrants. 相似文献
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黄土高原安塞县生态退耕情景及农业影响 总被引：16，自引：0，他引：16
退耕还林是目前黄土高原恢复生态环境和控制水土流失的主要政策。为搞清政策驱动下黄土高原生态退耕的基本情景,以安塞县为例,利用2000年土地利用图和地形坡度图,以地形坡度15o、20o和25o为退耕界限,借助GIS空间分析技术,模拟和分析了安塞县生态退耕的规模、空间分异特点及退耕补贴需求和对农业的影响。研究结果表明：安塞县合理的退耕坡度界限应在20o-25o之间,北部的镰刀湾、王家湾、化子坪、坪桥、郝树坪和南部的楼坪6乡镇可考虑退耕20o以上的坡地,其他8乡镇宜退耕25o以上坡地。 相似文献
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长江上游退耕还林工程合理规模与模式 总被引：2，自引：0，他引：2
陡坡耕地的水土流失对生态环境和农业可持续发展构成双重压力。退耕还林是促进人与自然协调，推动农业可持续发展的有效途径，但应避免退耕还林工程规模的盲目扩大。退耕还林的规模应根据自然条件、生态功能定位并考虑粮食安全保障以确定。地广人稀的金沙江中上游、盆周山地是长江上游最重要的水源涵养、水土保持功能区，其退耕还林规模可适度扩大，但川中丘陵区、三峡库区人口稠密，退耕还林不应过分追求规模，退耕后的林草地不应突破土地面积的40％。而退耕还林工程的实施更应注重模式的选择，防止一刀切，川中丘陵区、三峡库区退耕还林宜采用“旱坡地粮经弹性结构种植”技术，建立坡地农林复合系统，逐步实施退耕还林。 相似文献
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